High-speed illumination apparatus

ABSTRACT

A high-speed illumination apparatus advantageous for use in non-impact printers and character display devices. Rows of openings are provided on a rotatable drum, with the openings in each row forming a specific character or symbol such that the character or symbol of each row differs from the character or symbol of every other row. A large number of characters are provided in each row. In some applications, greater than 100 characters or symbols are provided per row. A line of characters to be either printed or displayed are examined for the purpose of illuminating lamps at positions in each row of the rotating drum which are present in the line of characters to be either printed or displayed. A single row of lamps is provided in a lamp assembly which is mounted in a stationary fashion within the drum. Those specified character positions of a particular row which are to be illuminated are enabled by energizing the cathode and anode electrodes of the selected lamps. A single trigger pulse is applied for igniting the lamps through a common conductive bar which has the dual function of operating as the trigger electrode and as reflector means for all of the lamps to concentrate illumination toward those selected characters formed within the row to be illuminated. The illumination may be converted into a character display through the use of a long-persistence, luminescent panel or, alternatively, may be printed through the use of either a paper having a light-sensitive coating or may be printed upon plain paper through the use of a transfer drum which transfers the image formed by a sensitized coating upon the transfer drum which is then transferred and imprinted upon the plain paper.

United States Patent Klockenbrink 1 Feb. 8, 1972 541 HIGH-SPEED ILLUMINATION APPARATUS [72] Inventor: Joseph M. Klockenbrink, Riverside, Conn.

[73] Assignee: Path Computer Equipment Inc., Stamford,

Conn.

[22] Filed: Feb. 24, 1969 [2]] Appl. No.: 801,635

Primary Examiner-John W. Caldwell Assistant ExaminerDavid L. Trafton Attorney-Ostrolenk, Faber, Gerb & Soffen [57 ABSTRACT A high-speed illumination apparatus advantageous for use in non-impact printers and character display devices. Rows of openings are provided on a rotatable drum, with the openings in each row forming a specific character or symbol such that the character or symbol of each row diflers from the character or symbol of every other row. A large number of characters are provided in each row. In some applications, greater than 100 characters or symbols are provided per row. A line of characters to be either printed or displayed are examined for the purpose of illuminating lamps at positions in each row of the rotating drum which are present in the line of characters to be either printed or displayed. A single row of lamps is provided in a lamp assembly which is m ounted in a stationary fashion within the drum. Those specifiedcharacter positions of a particular row which are to be illuminated are enabled by energizing the cathode and anode electrodes of the selectedlamps. A single trigger pulse is applied for igniting the lamps through a common conductive bar which has the dual function of operating as the trigger electrode and as reflector means for all of the lamps to concentrate illumination toward those selected characters formed within the row to be illuminated.

' which is then transferred and imprinted upon the plain paper.

6 Claims, 19 Drawing Figures PATENTEU FEB 8 I972 SHEET 6 OF 7 000.com...

M & w

HIGH-SPEED ILLUMINATION APPARATUS The present invention relates to lamp illumination techniques and systems, and more particularly to a high-speed illumination apparatus for use in high-speed nonimpact printers, character display devices, and the like, wherein high intensity illumination is obtainable at high operating speeds, making the system highly adaptable for use in nonimpact printers, character display devices, and the like, which are capable of operating at higher speeds and have longer operating lives not heretofore possible in conventional devices of this nature.

The use of printers as peripheral equipment in conjunction with computers is quite widespread. Computers presently in use are capable of operating at speeds well beyond the millimicrosecond range. However, such computers are limited in their effectiveness as a result of the slower operating speeds of printing devices employed as peripheral equipment in conjunction with the computer. Impact printers, which have heretofore been used in great numbers in computer and dataprocessing systems, have the disadvantage of requiring mechanical movement to produce the necessary impact which is typically in the form of reciprocating printing hammers. Relatively low operating speeds of such impact devices have led to the development of nonimpact printers which employillumination techniques usually in the form of flashlamps which momentarily and selectively illuminate or pass light through openings in the shape of characters, which shaped light beams are then caused to impinge upon either sensitized paper or a sensitized emulsion provided on a transfer drum in order to ultimately print the characters upon paper moving at a constant speed. One conventional technique which is now in widespread use utilizes a rotating drum having a plurality of rows of characters arranged around the surface of the drum, wherein each row is aligned substantially parallel to the longitudinal axis of the drum. A plurality of lamps equal in number to the total number of characters in each row are selectively energized to cause light to be passed through selected characters of a row for momentarily illuminating the sensitized emulsions provided on either a transfer drum or coated directly on the paper upon which the characters are to be ultimately printed. in order to achieve high-speed operation, the flashes of illumination must be of extremely short duration. In order to satisfactorily activate the sensitive emulsions mentioned hereinabove, it thus becomes necessary to cause the illumination to be of sufficient intensity to compensate for the brief interval of time during which the illumination is present. This necessitates the provision of lamps which are capable of achieving maximum illumination in the shortest period of time, and further capable of performing a large number of operations within a brief time interval.

Due to the large intensities required during illumination and the repeated number of operations required per unit time, the lamps utilized in the operation are found to dissipate a large quantity of heat which serves to deteriorate the lamp and appreciably cut down its useful operating life.

The present invention is characterized by providing an illumination system capable of energizing lamps at high rates of speed during extremely brief intervals of time wherein the light intensity of energized lamps is either significantly greater than that obtainable in conventional techniques or may be equal to the intensity capable of being obtained in conventional techniques through the use of significantly reduced operating and trigger voltages applied to such lamps, and which is further capable of rapidly dissipating the heat generated by such lamps during their operation to, therefore, appreciably increase the operating life of such lamps.

The present invention is comprised of an elongated drum adapted to rotate at extremely high speed. Rows of characters or other symbols are arranged at spaced intervals around the surface of the hollow drum, wherein each row is comprised of a plurality of either transparent or translucent openings of identical configuration, which configurations are in the shape of a particular character or symbol. The characters or symbols of each row difler from the characters or symbols of every other row around the drum.

associated lamp to remain within the channel to isolate the rays from any other channel and thereby prevent any spillover of illumination from one lamp to any of the adjacent channels.

Each of the lamps is provided with an anode and cathode electrode. The cathode-electrodes may be connected in common, while the anode electrodes are selectively energized by driving circuits operated under the control of logic circuitry to enable energization of selected lamps within a given interval of time during which a particular row of characters is positioned adjacent the honeycomb structure.

The lamps so enabled are triggered by energization of a trigger electrode which is in the form of a solid, elongated bar of conductive material having a plurality of substantially semicircularshaped grooves or cutouts arranged at spaced intervals along one side of the bar, each serving to embrace and position an associated lamp. The semicircular-shaped grooves are preferably plated with a highly reflective material which is further polished to provide a highly reflective surface for reflecting light rays impinging upon the material and thereby direct and concentrate substantially all of the light into the associated light channel for each lamp. The conductive bar performs a very specific function, namely: (1) reflecting light rays, (2) operating as the trigger electrode for all lamps, and (3) acting as'a medium for dissipatingheat generated by the lamps. Most prior art techniques employ a wire looped about the lamp to form one or more turns, which turns of wire are positioned about the exterior envelope of the lamp at a location substantially intermediate the ends of the envelope. This I technique has the disadvantage of blocking the light rays directed toward the turns of wire and thereby reducing the intensity of the flash passed through the character-shaped opening in the drum. The conductor bar has an appreciable thickness and embraces each lamp to a degree sufficient to assure rapid triggering of the lamp at pulse rates not heretofore possible and further capable of providing flashes of an intensity not heretofore possible in conventional techniques, or alternatively at intensities equal to those reduced trigger voltage levels.

Another preferred embodiment of the lamp array may be in the form of a single elongated cylindrical-shaped envelope hermetically sealed at both ends thereof and charged with a suitable ionizable gas. A large plurality of disc-shaped members are positioned in space parallel fashion relative to one another at regularly spaced intervals along the hollow cylindrical envelope which is preferably formed of a transparent material. The wafers may be either nonporous or porous so as to either isolate the gas contained within each compartment from adjacent compartments or may allow free passage of gas from one compartment to the next. The disc-shaped members form a plurality of individual compartments each of which may be considered to be the equivalent of a single discharge lamp of the type described above. Each compartment is provided with a pair of electrodes partially projecting into each compartment and partially extending beyond the exterior of the envelope for connection to electrical charging circuits. Each pair of electrodes for a single compartment are aligned along a diameter of the cylindrical-shaped envelope and are spaced by an amount sufficient to cause a gas discharge within the compartment. The trigger electrode in this embodiment takes the form of an elongated sheet of conductive material having an arcuate-shaped cross-sectional configuration. The conductive plate is placed against the outer surface of the multilamp envelope and merely surrounds one-half of the envelope. The plate is formed of a metal having good conductive properties and is coated with a material having good reflective characteristics, which coating is further polished to produce high reflectivity. The conductive plate performs the functions of triggering the individual lamp compartments carrying heat away from the multilamp array and concentrating light energy generated within the compartments toward the region of a surface which is to be illuminated at selected areas along such surface.

In one preferred system embodiment which operates as a high-speed nonimpact printer, a plurality of input terminals are provided for receiving coded information representative of a message. The incoming information applied to each of the input terminals may be processed simultaneously and is applied to the input terminals in digital form in sequential fashion until each character, or a group of characters, has been shifted into a first group of buffer registers provided for each input terminal. As soon as the shift registers are loaded, their contents are shifted in parallel to a second group of buffer registers provided for each input terminal. Since the system is adapted to print characters represented by the ASCII code format, while being capable of receiving coded information in any other code from such as teletype, baudot, binary coded decimal, and the like, a code converter is provided for converting each of the non-ASCII code formats into the ASCII code format. Obviously, those messages applied to input terminals which are already in the ASCII code format may bypass the code conversion operation.

After completion of the code conversion operation (or after receipt of a message already in the ASCII code format), the messages are transferred to memory means capable of storing a large number of messages at any given time. Each message transferred to an input terminal is identified by a signal which identifies the end of a message which is stored in the memory means and which further is employed to set an enabling circuit which indicates the fact that a completed message from a specified input terminal has now been fully received. In the preferred embodiment, the memory means is comprised of a disc memory wherein each disc is provided with a plurality of tracks, each having a read/record head associated therewith.

The printing operation is initiated only upon the receipt and storage of an entire message within the memory means. The printer is provided with a synchronizing circuit which may take the form of a disc mounted to rotate with the character drum. The disc is provided with one or more openings or slits which are designed to pass light from a light source positioned on one side of the disc for pickup by a light-sensitive phototube positioned on the opposite side of the disc, once or more per revolution of the disc (and hence once or more per revolution of the drum). Illumination of the light-sensitive phototube immediately indicates that the predetermined row" of characters is now about to pass the honeycomb structure in readiness for illumination of any selected character positions along the row of characters which comprise the predetermined row. The message is transferred from disc memory to a portion of core memory where it is then shifted out into a buffer register character-by-character per line of character where the first character and line is compared against the code for the character of the predetermined row to generate an enabling signal for each selected character position in the predetermined row". After all of the characters for the row to be printed have been examined, the trigger electrode for the flashlamp array is energized, causing illumination of only those selected lamps representing the presence of those selected characters within the line to be printed. As soon as the last character of the row to be illuminated is examined for comparison against the character shifted into the buffer register, the coding circuitry and counter for the lamp illuminating logic is reset just prior to the movement of the next row in sequence to examine the comparison of the characters stored in the buffer register against the next row of characters. This operation is continued until the drum completes one full revolution, at which time the counters and registers are reset and the next character from memory is shifted into the buffer register to be examined in a similar manner. Thus, each character of the message to be printed is compared against the codes for each of the characters arranged in rows about the drum and is illuminated to activate the sensitized emulsion within one complete revolution of the drum which, in one preferred embodiment, has been designed to rotate at a speed of 1,200 rpm. Thus, in one typical example wherein each line or row printed contains I20 characters, information may be printed out at the rate of 600 lines per minute. However, rather slight modifications can be made in the system to print lines each containing or more characters at the rate of 600, 1,200, 3,600 and even 7,200 lines per minute or greater, if desired. Thus, the system is capable of printing characters at the rate of more than 850,000 characters per minute.

In another preferred embodiment, the image drum and illumination means of the present invention may be employed in a character-display system wherein the illuminated light passing through each of the images arranged around the drum may be caused to impinge upon either a ground glass medium or a memory phosphorous material having a persistence or lightretaining characteristic to yield a visually observable display which may persist for any time duration desired or dictated by the needs of a particular application. In the case where the shaped light beams (formed in the configuration of a particular character by the image drum) impinge upon a ground glass medium, the illumination for each row of characters may be repeated during each repetitive revolution of the drum. Since the human eye is incapable of distinguishing motion at rates higher than 20 frames per second, at a rotational speed of 1,200 rpm. the selected characters of any particular row in the drum will be illuminated at a rate of 20 times per second having the effect upon the human eye of presenting a substantially continuous image of such characters. Obviously, this repetition rate can be substantially increased by doubling the number of rows of characters provided around the surface of the image drum, thereby causing each particular character to be illuminated twice per revolution, increasing the illumination rate per second to 40 per second which would unequivocally cause a human eye to consider the display as being one which is continuously illuminated since the human eye is not capable of detecting the presence of flicker at such a high rate.

It is, therefore, one object of the present invention to provide a novel illumination array for use in high-speed, nonimpact printers, character display systems, and the like, which is capable of generating high-intensity illumination at very rapid repetition rates which was heretofore not capable of being produced by conventional techniques.

Another object of the present invention is to provide a novel illumination array for use in high-speed, nonimpact printers, character display devices, and the like, which incorporates a novellamp array utilizing a common trigger electrode for the flashlamps of the array which single component serves the functions of triggering the energization of the lamps of the array, concentrating all of the illumination of the lamps in a first direction to thereby increase the light intensity employed to expose an image and acting asa heat dissipating device for rapidly dissipating the heat generated by the array of lamps.

Still another object of the present invention is to provide a novel high-speed, nonimpact printer capable of printing messages upon either plan or sensitized paper, which messages are accepted from a plurality of independent sources wherein the high operating speeds obtainable result from the use of a novel illumination array.

These as well as other objects of the present invention will become apparent when reading the accompanying description and drawings in which:

FIG. 1 is a schematic diagram showing a conventional flashlamp and energizing circuit.

FIG. 1a shows an end view of the flashlamp of FIG. 1.

FIG, 2 shows a perspective view of a portion of a lamp array embodying the principles of the present invention.

FIG. 2a shows an end view of the array of FIG. 2 and FIG. 2b shows the top view of a portion of the array of FIG. 2.

FIG. 20 is a perspective view shown in exploded fashion depicting another preferred embodiment of the lamparray.

FIG. 3 is a for illuminating diagram of a circuit utilized for energizing selected lamps in an array of the type shown in FIG.

FIG. 4 is a perspective view, partially sectionalized, of an image drum incorporating a lamp array of the type shown in FIG. 3.

FIGS. Sa-Sd show side, end, top and exploded top views, respectively, of the honeycomb structure shown in FIG. 4.

FIGS. 6a and 6b are elevational and exploded views, respectively, of two preferred embodiments for the image-drumdrive systems.

FIG. 7 is a block diagram showing a high-speed nonimpactprinter system employing the image drum and lamp array of FIGS. 2 and 4.

FIG. 8 shows a block diagram of the circuit logic employed for selectively energizing the lamp array of FIG. 2.

FIG. 9 is a perspective view showing the image drum of FIG. 4 employed in a character-display system.

FIGS. 10 and 11 are elevational views showing alternative printing systems utilizing the image drum assembly of the present invention.

FIG. 1 shows an energizing circuit 10 for a miniature gas discharge lamp l1 comprised of a glass envelope l2 enclosing anode and cathode electrodes 13 and 14, respectively, portions of which project from the envelope for connection to an electrical circuit. A gas is provided within the envelope which is capable of being ionized upon the application of a voltage across the anode and cathode electrodes in conjunction with the simultaneous application of a high voltage pulse to the trigger electrode 15 of the lamp which consists of at least a single wire loop surrounding the exterior of envelope l2 and being positioned substantially intermediate the innermost ends of the anode and cathode electrodes 13 and 14, respec tively. A voltage V, is applied across the input terminals 16,16 of the energizing circuit to develop substantially the voltage V across a capacitor C connected across the anode and cathode electrodes. The voltage V., is normally maintained across input terminals 16,16 when the lamp is in its quiescent state. As soon as it is desired to illuminate the lamp, the voltage V appearing across input terminals 16,16 is removed and replaced by substantially a short circuit condition, by rendering the SCR 125 conductive, causing the capacitor C to discharge the voltage across its plates through the gas discharge lamp 11. Upon the simultaneous application of a large magnitude trigger pulse voltage, the trigger electrode 15, the gas contained within envelope 12 will become ionized and thereby emit light in an omnidirectional fashion as shown by the light rays depicted by the arrows 17 in FIG. 1a. 7

The present invention is concerned with providing a lamp design by which the electrical energy dissipated per flash through a miniature gas discharge lamp can be reduced through the use of a novel reflector made of an electrically conductive material.

The life of a miniature lamp of the type shown in FIG. 1 is determined by the energy dissipated per flash and the number of flashes per second. A part of the energy dissipated in the lamp is converted into electromagnetic radiation lying in both the visible and invisible range of the spectrum. The spectral output is controlled by the characteristic of the type of gas, the gas pressure and the transmission property of the glass used to form the lamp envelope. As shown in FIG. 1a, the radiant energy is emitted in an omnidirectional fashion such that energy arriving at a point P which is spaced a distance d from the lamp is a function of the arc length L, the surface intensity I of the arc and the distance d between the lamp and the point P being illuminated. The illumination intensity E may thus be expressed by the equation: E=k LI/d where k is a constant of proportionality.

In the conventional embodiment of FIGS. 1 and 1a the intensity of the illumination at point P is significantly reduced as a result of the fact that the illumination from the lamp I1 is omnidirectional causing a large amount of the illumination to be lost. In addition thereto the wire loop electrode 15 wrapped around glass envelope 12 acts to block a significant portion of the emitted light, still further reducing the light intensity at the point P. Also, the heat generated as a result of the flash produced by the lamp is not rapidly dissipated causing undue and prolonged heating of the lamp elements which act to deteriorate the lamp and thereby significantly reduce its useful operating life as well as being capable of causing the formation of an unstable are. 7

The present invention provides a novel lamp array as shown in FIGS. 2-2b which utilizes an elongated bar 20 of conductive material which is machined or otherwise formed along one face thereof to form a plurality of semicircular-shaped grooves 21 arranged at regularly spaced intervals. Each of these grooves is coated with a highly reflective material which is further highly polished to form an excellent reflecting surface. As an obvious alternative, the elongated bar 20 may be formed of a metallic conductive material which when highly polished has the inherent characteristic of acting as an excellent reflector. Miniature gas discharge lamps 11 are positioned within each of the highly reflective semicircular grooves 21 (only three of which are shown in FIG. 2 for purposes of simplicity). The elongated conductive bar is coupled to a suitable lead 22 (see FIG. 2b) which is coupled to a high-voltage trigger pulse source (not shown) for application of the trigger pulse voltage to the conductive bar in conjunction with the anode-energizing voltage applied to selected ones of the individual gas discharge tubes within the array. As shown best in FIG. 2b, the illumination of a single lamp causes light rays to be emitted in an omnidirectional fashion. However, the highly reflective characteristics of the semicircular groove housing the gas discharge lamp 11, shown in FIG. 2b, causes the rays impinging upon the reflective surface to be directed and substantially concentrated toward the point P to be illuminated, thereby greatly increasing the magnitude of the illumination intensity at point P even assuming the trigger voltages, anode voltages and tube characteristics to be the same as are employed in conventional devices. As an obvious, alternative, the same illumination intensity can be obtained through the use of significantly reduced trigger and anode voltage levels, thereby reducing the amount of heating experienced by the lamp while maintaining the same light intensity at the illuminated point P. In addition thereto, the semicircular grooves make contact with a substantially large surface area of each glowlamp as compared with the single loop trigger electrode 15, shown in FIG. 1, to greatly enhance the effect of the trigger voltage applied to conductor bar 20. In addition thereto, as a result of the highly conductive properties of bar 20, the amount of heat generated by each lamp during a flashing operation is rapidly conducted away from the lamps by the bar 20 and dissipated over an extremely large surface area as compared with the surface area of an individual lamp, thus greatly enhancing the useful operating life of the lamps. Another significant feature of the conductor bar 20 resides in the fact that the conductive bar does not completely surround the lamp as is the case with the wire loop 15, which loop serves to block some of the illumination directed toward the point P so as to still further increase the illumination intensity at the point P.

The above features all contribute toward an increase in the flux density of illumination, permitting a reduction in the electrical energy dumped into the lamp by capacitor C, shown in FIG. 1 and further allows an increase in the pulse rate which can be as much as double conventional pulse rates without any increase in operating temperature. It is thus possible to selectively trigger the operation of a large array of lamps arranged in side-by-side fashion, as shown in FIG. 2, and thereby control the firing of a large number of lamps within the array by a single trigger electrode of relatively simple design.

FIG. 20 shows another preferred embodiment for the lamp array of FIG. 2b and is comprised of a hollow elongated envelope formed of a suitable transparent material such as glass. The ends 1500 and l50b of the glass envelope are hermetically sealed and contain a suitable ionizable gas such as, for example, Xenon. A plurality of disc-shaped members 151 of a suitable insulating material are arranged in spaced parallel fashion within the interior of envelope 150 at regularly spaced intervals along said envelope. These members may either be porous or be provided with openings to allow for the passage of the gas contained within the envelope between and among the various compartments defined by each pair of disc-shaped members 151. Alternatively, the disc-shaped members may be formed of a solid nonporous insulating material which isolated the gas captured within each compartment.

A first group of anode electrodes 152 each extend into an associated one of the compartments as well as extending beyond the exterior of envelope 150 for connection to external charging circuits. The anode electrodes 152 are arranged in spaced parallel fashion withrespect to one another and are further radially aligned relative to the cylindrical-shaped glass housing 150. In a similar fashion, the second group of cathode electrodes 153 are provided which electrodes project into an associated compartment and extend beyond the exterior of glass envelope 150 for connection to the electrical charging circuitry. The electrodes 153 are arranged in spaced parallel fashion and are aligned along the same radial plane as electrodes 152.

The trigger electrode for all of the lamp compartments" is comprised of an elongated sheet 154 formed of a suitable metal having good conductivity. Conductive sheet 154 has an arcuate shaped cross-sectional configuration and, while not shown in FIG. 2c, is placed in surface contact with the rearward face of glass tube housing 150. The conductive sheet 154 is thus positioned in close proximity to all of the lamp compartments provided along envelope 150 to perform the three functions previously mentioned, namely, operating as a trigger electrode for the lamp compartments; concentrating light rays (in the manner shown by dotted lines 155 and 156) upon a specific region along a surface 157 to be exposed; and further acting to carry heat generated by each of thelamp compartments" which are discharged so as to assure cool operation of the unit. The embodiment of FIG. 2c is superior to the embodiment of FIG. 2 in cases where the lamp array is being utilized in applications having severe packaging restrictions.

FIG. 3 is a schematic diagram showing circuitry capable of selectively energizing a plurality of such lamps which may be arranged in an array of the type shown in FIG. 2 (only a few of such lamps being shown in FIG. 3 for purposes of simplicity).

As shown in FIG. 3, the lamps 11 are each comprised of an anode electrode 13 having a diameter which is substantially continuous along its entire length. The cathode electrode 14 is provided with a bulb-shaped tip 140 employed to enhance the gas discharge. The envelope is preferably filled with Xenon, however, any other suitable ionizable gas may be employed. Each of the flashlamps 11' are provided with a circuit for applying a voltage across the anode and cathode electrodes (only one of which is shown in FIG. 3 for purposes of simplicity). The circuit is substantially similar to that shown in FIG. 1 wherein (in the quiescent state) a voltage of 400 volts is applied across terminals 16,16 causing a voltage of substantially 400 volts to be developed across capacitor C. The moment that any of the lamps are to be energized, the 400-volt supply is short circuited by triggering the SCR connected in series with the lamp 11' to conduct, the operation of the SCR being more fully described in the description of FIG. 8. This causes the capacitor C to discharge the voltage across its plates through its associated SCR and gas discharge lamp. Simultaneously therewith a trigger pulse, shown by waveform 25, is applied to the trigger electrode 27 of a silicon-controlled rectifier 26 having its anode and cathode electrodes 28 and 29 con nected between a voltage supply capable of applying between 100-200 volts DC, and ground bus 30. The trigger pulse represented by waveform 25 turns on the SCR 26 causing the energy stored in capacitor C1 to be discharged and thereby generate a pulse in the primary 32 of transformer 31 which is 8 l stepped up to a larger amplitude voltage pulse through the secondary winding 33 which has a larger number of terms in primary winding 32 so as to apply a high-voltage pulsesimultaneously to all of the trigger electrodes 20 of each lamp within the array. Although FIG. 3 shows the trigger electrode 20 as being a half-loop" of thin wire, it should be understood that this is done merely for purposes of simplicity and that each trigger electrode is actually of the form shown in FIGS. 2-2c.

FIG. 4 shows the image drum assembly 40 incorporating the light array assembly of FIGS. 2-2c. The drum 41, in one preferred embodiment, is formed of a transparent material to allow for the substantially free passage of light therethrough. A film negative 42 is wrapped around the exterior surface of drum 41. The film negative is black (i.e., opaque) substantially over its entire surface except for those portions at which a character is located which are transparent. FIG. 4, for purposes of simplicity, shows the film negative as being white and the characters as being black, but it should be understood that the actual configuration is reversed from the manner depicted in FIG. 4. The characters are arranged in rows such as, for example, the rows 43-48. Only a few such rows have been shown in FIG. 4 for purposes of simplicity, it being understood that each row would be spaced at equal intervals from its adjacent rows around the entire circumference of the drum. Each row contains a plurality of substantially the identical character, the rows 43-48 containing the identical characters 8, 9, A, B, C," D and E, respectively. It should be un derstood that the characters in each row extend over substantially the entire length of the drum with each row containing as many as or more characters. In one preferred embodiment, each row may contain identical characters.

As an obvious alternative, the transparent drum and film negative may be replaced by a single drum member formed of an opaque material which is machined or otherwise formed with a plurality of openings arranged in regular rows wherein each opening is cut in the shape of a particular character, number, or other symbol. While alphanumeric information is shown on the drum of FIG. 4 it should be understood that symbols such as punctuation marks, algebraic symbols such as plus and minus signs or characters of any other language may be arranged around the drum.

FIGS. 6a and 6b show two alternative embodiments for rotating the drum assembly 40. In FIG. 6a the drum is shown as being provided with a pair of cylindrical discs 44 and 45 secured to opposite ends of the drum. Each of these discs is provided with a suitable collar 46 and 47, respectively, for experiencing freewheeling rotation about a shaft 48 which is fixedly secured atits ends to a pair of supporting brackets 49a and 49, respectively, which, in turn, are mounted upon a supporting member 50. A synchronous motor 51 having an output shaft 52 is secured upon horizontal supporting plate 50. A pulley 53 is secured to the output shaft of synchronous motor 52 while a second pulley 54 is rigidly secured to drum shaft 48. A belt 55 which is entrained about pulleys 53 and 54 serve to transmit rotation of the motor output shaft 52 to the pulley 54 which is secured in any suitable manner to end disc 45 to impart rotation to drum 41. In one preferred embodiment, the synchronous motor operates to rotate the drum at a speed of 1,200 rpm. The actual rotating speed of the drum, however, may be adjusted, depending upon the particular application.

FIG. 6b shows a slightly modified arrangement for rotating drum 41 wherein the drum is provided with a circumferential groove 56 for seating belt 55 which is entrained about groove 56 and synchronous motor pulley 53 and thereby impart rotation to drum 41 and eliminate the need for pulley 54.

A lamp array of FIG. 2 is positioned in a stationary fashion within the interior of drum 41 as shown in FIG. 4. The conductive bar 20 is secured between a pair of flat elongated boards 60 and 61 and is aligned so that the semicircular-shaped grooves are pointed in a downward vertical direction relative to FIG. 4. The drum shaft 48 which is rigidly secured at its ends by plates 49 and 49a, shown in FIG. 6a, and thereby restrain from experiencing any rotation whatsoever, is provided with an elongated collar 62 surrounding and rigidly secured to shaft 48. The collar is provided with a pair of downwardly depending flanges 63 and 64 either rigidly secured to collar 62 by any suitable fastening means or alternatively, integrally formed with collar 62. An elongated member 65, having its upper portions positioned between flanges 63 and 64 is rigidly secured thereto by fastening means 66. A second pair of plates 67 and 68 have their upper marginal edges secured to member 65 by fastening means 69 and have their lower ends secured by fastening means 70 which, in turn, maintain plates 60 and 61 in spaced parallel fashion in the manner shown in FIG. 4.

FIGS. Sa-Sd show various views of the plates 60 and 61 wherein FIGS. Sa-Sc show side, end and top views of plate 60, for example, which is substantially identical to plate 61 and additional views of plate 61 have therefore been omitted for purposes of simplicity, it being understood that the configuration of plate 60 which will now be described is identical in every respect to plate 61.

Plate 60 is an elongated substantially rectangular shaped board having a narrow elongated opening 72 and a plurality of small apertures 73 arranged near the four corners of the plate for receiving the fastening means 70, shown in FIG. 4. One surface of the plate 60 is machined or otherwise grooved to form a plurality of narrow elongated slots running the entire length of side 74. The slots are of extremely small width and depth (the width being of the order of 0.0140.0l6 inch and the depth being in the range from0.0l0.020 inch) and are arranged at spaced intervals of the order of one-tenth of an inch apart.

When boards 60 and 61 are positioned in spaced parallel fashion (by spacers 600, only one being shown in FIG. 4) in the manner shown in FIGS. 4 and d, the elongated grooves are aligned to face one another in a uniform manner. Thin elongated strip 75 is of a substantially rigid and opaque material and is positioned to be embraced by associated grooves of the plates 60 and 61 in the manner shown best in FIG. 5d. These strips extend from the lower edge 76 of the plates up to imaginary line 77, shown in FIGS. 5a and 5b.

The individual lamps are positioned within the elongated openings 72 in the manner shown in FIGS. 5a and 5b so that their anode and cathode electrodes 13 and 14 extend beyond the exterior surfaces of plates 60 and 61. The elongated bar is positioned above the lamp array in the manner shown in FIGS. 5a and 5b so that the semicircular-shaped reflective surfaces embrace the lamps along their upper sides and thereby extend downwardly to a point where the narrow rectangular surfaces 21a (see FIG. 2) between each of the reflective surfaces 21 are substantially in alignment with imaginary line 77. The thin elongated strips 75 have their upper edges touching the surfaces 21a so as to substantially completely surround each of the lamps within the array and thereby confine the light radiated by the lamps to only its associated channel 78 (see FIG. 5d) which channels are defined by each of the surfaces 74 of boards 60 and 61 and the opposing surfaces 79 of the narrow elongated strips 75.

The plates 67 and 68, shown in FIG. 4, are provided with suitable openings and guideways (not shown) for receiving the anode and cathode electrodes of the discharge lamps and for connecting these electrodes to suitable conductive leads (not shown for purposes of simplicity) so as to connect the lamps to circuits of the type shown in FIG. 3, which circuits are mounted upon a printed circuit board arrangement 80 containing a printed circuit configuration and having mounted thereto the various circuit components such as resistors, capacitors, transistors, SCRs and the like, shown generally by the numeral 81. The contacts to the appropriate terminals of the electrical circuits provided on circuit boards 80 are made through the guiding blocks 67 and 68, respectively.

FIG. 7 is a block diagram showing a system 85 for printing out messages employing the image drum and light array assembly of the present invention and is comprised of a plurality of input terminals 86-1 through 86-n connected toa datacommunications'interface 90, which input terminals are capable of accepting messages from a plurality of separate sources. In one preferred embodiment up to 32 separate input terminals may be provided. Polling of incoming messages is performed by the data interface circuitry upon voice grade lines which may be transmitting at rates of up to 4,800 bits per second. The polling is performed by circuits 87-1 through 87- n which initiate requests for data. If a message is to be transmitted, circuits 87-1 through 87-n operate to transfer incoming messages in sequential fashion into shift registers 881 through 88-n, respectively. The shift registers may be comprised of 11 stages for receiving any one of a plurality of code formats. As soon as one character is loaded into shift register, it is transferred in parallel fashion to a second register 89-1 through 89-n, respectively provided for each incoming line. Each of the second buffers 89-1 through 89-n may be selectively coupled to a code conversion circuit 91 which, in one preferred embodiment, may employ a core matrix in conjunction with logic circuitry for performing a code conversion upon those code formats which are not in ASCII format The code conversion circuitry is provided with a capability for performing conversion on two separate lines at any given time. Since each of the code-conversion circuits shown are substantially identical in design and function, only one will be described herein for purposes of simplicity. Logical circuitry 92-1 compares the code format in register 89-1 with the standar ASCII character stored in core group 93-1. Upon the lack of each compare an output signal is provided by logic circuit 92-1 at its output terminal 92-1a causing a counter 94-1 to be stepped and causing the standard character to have its right-hand-most bit shifted to the left-hand-most bit position through line 93-1a while the remaining bits are shifted one bit position to the right. A count in counter 94-1 is continued until a comparison is detected by logical circuitry 92-] which causes counter 94-1 to step once more. At this time, counter 94-1 contains the code format in ASCII code which is the equivalent for the code format stored in register 89-1 which is being converted.

Each polled input line is identified by circuit 87-1 as to the type of code that they are transmitting (i.e., binary coded decimal, dot, tele type and so forth).

If the circuits 87-] through 87-n receive an indication that an ASCII code format message is being transmitted, the signal appearing at output line 87-la through 87-na is applied to logical gating circuit 921 (or 92-2). An immediate transfer can then be made through the output terminals 92-Ia (or 92-2a) into the storage means 95. i

Storage means 95, which may be any suitable memory means, is designed to store a large quantity of messages prior to printout. In one preferred embodiment, the storage means 95 may be a disc memory which is shown in FIG. 7 (for purposes of simplicity) as being a disc 96 having a plurality of read/record heads 97-1 through 97-4 each assigned to a particular track of the disc 96. It should be understood that a greater number of read/record heads and associated tracks may be provided in an actual embodiment and the quantity shown herein has been limited to a few in number for purposes of simplicity.

Each of the tracks such as, for example, the track 98-3 is divided into quadrants 98-30 through 98-3d wherein the smallest message will be assigned to at least one quadrant of a memory track even though it may not occupy the entire quadrant. Obviously, messages of greater length can occupy more than one quadrant and likewise may occupy ore than one track. Buffer storage means utilized in the preferred embodiment is chosen to have the capability of storing up to 23 pages of information wherein a page is comprised of that number of characters that can be contained (in typewritten fashion) on a typical S /XI l-inch page. The reason for selecting such a large storage capability is that the entire message will first be recorded in the buffer memory before initiation of printout. Transmitted messages are normally followed by an end of message (EOM) signal on the termination of a message, thereby providing an indication to the buffer memory means 95 that printout may now be initiated. Preferably, coded messages stored in memory are read out in a nondestructive manner to allow a large plurality of copies to be made without the need for resorting to a duplication process, such as through the use of copier machines.

The logical circuitry of the core memory and logical-gating means 91 may be employed to allocate tracks of the disc memory to incoming messages. As is conventional in disc memories, each track is capable of storing a total number of binary bits equal in number to each of the adjacent tracks. The manner in which this is achieved is through the use of a higher frequency read-in and readout rates for tracks of smaller circumference and conversely a lower frequency read-in and readout rate for tracks of larger circumference.

In the preferred embodiment, disc memories may be provided with or more tracks per disc which operates at rotating speeds of 3,400 r.p.m. and each disc has a capability of storing up to 4 pages per track or one page per quadrant where the quantity per page is as defined hereinabove.

While a disc memory has been described herein as being employed for the buffer memory means 95, it should also be understood that rotating magnetic drums may be employed with equal success. Drums are generally available which have the capability of storing data in 10 or more tracks at rotating speeds of 3,400 r.p.m. Judicious selection of the appropriate drum can also yield a storage capacity of 4 pages per track.

As soon as at least one message has been completely stored in buffer means 95, a printing operation may begin. The logical circuitry provided in computation section of the core memory and logical gating circuitry 91 may be utilized to direct readout of a fully stored message to the printer logic and lamp driver circuits which, as previously described, may be mounted within the image drum 40. Operation of the printer logic and lamp driver circuits will cause selective illumination of the lamp array for the purpose of printing a message on either plain or sensitized paper, in a manner to be more fully described.

FIG. 8 shows the logical circuit diagram of the printer logic and lamp driver circuitry 95a. In operation, the control logic circuitry of system section 91 will cause a portion of the message to be read out in an allocated portion of core memory 96 (shown in FIG. 8) which may be a matrix portion of core memory comprised of 9 rows and 512 columns of cores capable of storing a total of 4,608 bits, a portion of which comprises the message and the remaining portion of which comprises the addresses of each of the characters which have been transferred to the address register and output register portions 96-1 and 96-2 of core memory.

As was previously described with regard to FIG. 6a, the rotating image drum of assembly is provided with synchronizing means comprised of the disc 97 having a narrow slit (not shown) to allow light from light source 98 to impinge upon a light sensitive phototube 99 once or more per revolution of the image drum 41. Light-sensitive means 99 may take the form of a photosensitive semiconductor device, shown in FIG. 8, which generates a pulse on line 100 for resetting a binary counter 101 and simultaneously resetting address register 96- 1 to cause the next group of characters to be printed to be shifted into the designated section of core memory.

The address position of the first character in core memory causes that character in the output register 96-2 to be shifted into register 102. Each of the bit positions of the coded character in shift register 102 is applied to a plurality of logical AND-gates 103-1 and 103-3 through 110-1 and 110-3, respectively, through output lines 102-1 through 102-8, respectively. Simultaneously therewith, the output lines 101-1 through 101- 8 of binary counter 101 are applied to the input gates of 103-1 and 103-2 through 110-1 and 110-2, respectively, of a binary comparator logic circuit 111. Since each of the gate groups in binary comparator 111 are substantially identical, only one such group will be described herein for purposes of simplicity.

Each of the gates is of the NAND-gate-type wherein when all of the inputs to the gate are at binary l the output is at binary 0 and wherein the output is binary 1 when less than all of the input terminals or none of the input terminals are at binary I. Let it be assumed that the binary states applied to lines 101-1 and 102-1 are both binary 0. These inputs will cause gate 103- 1 to generate a binary l at its output which is simultaneously coupled to associated input terminals of gates 103-2 and 103- 3 The binary 0 levels on input lines 101-1 and 102-1 are further applied to associated input terminals of gates 103-2 and 103-3. Both of these gates receive binary 0 levels at their input terminals causing their output terminals to go to binary l, which states are combined in an output bus 112.

Assuming the binary levels appearing at lines 101-1 and 102-1 are both at binary 1 level, these inputs will be applied to gate 103-1 causing its output terminal to go to binary 0, which states will be applied to associated input terminals of gates 103-2 and 1033. Since a binary l and binary 0 level are applied to each of these gates, their outputs will go to binary l indicating a favorable comparison, which condition will be applied to common bus 112. In the final example, let it be assumed that lines 101-1 and 102-1 are at the binary 0 and binary l levels respectively. This will cause the output of gate 103-1 to go to binary l causing the outputs of gates 103-2 and 103-3 to go to binary l and binary 0, respectively, which conditions are applied to common bus 112.

Gate groups 105-1 through 105-3 and 106-1 through 106-3 are outputted to a second common bus 113; gate groups 107-1 through 107-3 and 108-1 through 108-3 are outputted to common bus 114; and gate groups 109-1 through 109-3 and 110-1 through 1103 are outputted to common bus 115, respectively. These common buses appear as inputs to gate 116. The operation of the binary comparator is such that when any of the gates outputted to a bus is binary 0 this bus will remain at the binary 0 level in spite of the fact that any of the othcrgatcs outputted to the same bus are at binary 1. Thus, in the case of a lack of comparison, at least one binary 0 state will be outputted to at least one of the buses causing at least one binary 0 state to be inputted to gate 116, thereby causing its output 116a to go to binary 1. This binary level is inverted by invertor gate 117 whose output 117a goes to binary 0 state, thereby disabling a group of gates 1 18-1 through l18-n.

In the case where a comparison exists between all bits of counter 101 and all bits in register 102, the outputs of buses 112 117 will apply binary 1 levels to the inputs of gate 116 causing its output to go to binary 0. This state will be inverted to a binary 1 condition by inverter gate 117 which will apply its output to gates 118-1 through l18-n for enabling these gates in a manner to be more fully described.

As was previously described, the light-sensitive device 99 is energized once or more per revolution of the drum indicating that the next row of characters upon image drum 41 will be the predetermined row. It now becomes an objective of the logical circuitry of FIG. 8 to energize only those lamps of the predetermined row which will illuminate letters of the predetermined row whose code format is that contained in shift register 102. This operation is performed through the use of binary coded decimal counter and decoding circuits 119 and 120 which operate at high speeds to step through each of the end positions assigned to each of the end lamps 11-1 through 11-n comprising the lamp array. The stepping of the counter and decoder circuits 119 and 120 may be controlled by an oscillator 121 which generates pulses at an output which will be synchronous with the rotation of image drum 40. These output pulses are applied through line 122 to the stepping input of the units binary coded decimal counter and decoder 119. The manner in which the circuits 119 and 120 am reset will be subsequently described hereinbelow. For the purpose of understanding the operation of the circuits 119 and 120, let

it be assumed that a reset pulse is applied to their reset input terminals 119a and 120a through an output line 123 coupled to the output of reset gate R which operates in a manner to be more fully described. Let it be assumed that the first stepping pulse of oscillator 121 is applied to the units circuit 119 which has just been reset so that all of its output stages are in binary 0. Upon receipt of the first pulse, output terminal 119-1 will go to the binary 1 state applying a binary '1 level to gate 118-1 while the remaining output terminals 119-2 through 119-l0 will remain at the binary level. The next stepping pulse from oscillator 121 causes output terminal 119-1 to go to binary 0 and output terminal 119-2 to go to binary 1 state while the remaining output terminals 119-3 through 119-10 remain in their binary 0 states. This operation continues in a similar fashion until output terminal 119-10 goes to binary 1. At this time unit circuit 119 generates an output pulse appearing on line 124 causing the l0s circuit 120 (which was previously reset to O) to generate a binary I level at its output 120-1 (indicating that at least stepping pulses have been applied to units circuit 119). In the preferred embodiment shown in FIG.

8, let it be assumed that 80 lamps are provided in the lamp array. In this case only nine output terminals 120-1 through 120- 9 need be provided in l0s circuit 120.

The output leads 119-1 through 119-10 are selectively coupled to each group of ten gates 118-1 through 118-n in the following manner:

Output'line 119-1 is connected to an associated input terminal of gates 118-1, 118-11, 118-21, 118-31 118-71; output line 119-2 is connected to gates 118-2, 118-12, 118-22 118-72; and finally, line 119-10 will be connected to associated input terminals ofgates 118-10, 118-20, 118-80. In a somewhat similar fashion, the output lines of l0s circuit 120 will be coupled to the gates 118 in the following manner:

Linc 120-1 is connected to associated input terminals of gates 118-10 through 118-l9; line 120-2 is connected to associated input terminals of gates 118-20 through 118-29; and finally, line 120-9 is connected to associated input terminals of gates 118-1 through 118-9. The signals provided at the outputs of units and l0s circuits 119 and 120 are selectively applied to the inputs of gates 118-1 through 118-n so as to energize only one such gate at any given instant of time. Simultaneously therewith, the comparison operation is being performed between the coded character in counter 101 and the character shifted from memory into register 102. The coded character in counter 101 will represent the row of characters in the starting row", for example, the character A.

Let it be assumed that the character stepped into register 102 is the first character of a message to be printed. At this time binary counter 101 will contain the ASCII code format representing the character (A) in the starting row of the image drum. A comparison operation will be performed by binary comparator 111 simultaneously with the setting of l0s and units circuits 119 and 120, respectively, having their output lines 119-1 and 120-9 in binary l state. All of the lines of the units and l0s circuits will be at binary 0 level. This will cause only gate 118-1 to be enabled at this time. Assuming that a comparison exists, three binary 1 states will be present at the associated inputs of gate 118-l causing its output to go to binary 0 level. This voltage level is appropriate to set SCR 125-1 which will remain set even after removal of the binary 0 state from the output of gate 118-l unless and until reset by means (not shown) coupled to lead 127-1 which will ground terminal 127-1 and thereby reset the SCR.

A brief instant after the first comparison operation is performed, output register 96-2 will shift the second character of the first line of characters to be printed into register 102 simultaneously with the application of the next shift pulse from oscillator 121 to the units circuit 119. This will cause line 119-l to go to binary O and line 119-2 to go to binary I, while the remaining lines 119-3 through 119-10 remain set at the binary 0 level. Thus, the output lines 120-9 and 119-2 provide binary 1 inputs to gate 118-2. Assuming the next character, now in shift register 102, to have the same code format as the second character positioned in the starting row", the binary comparator 111 will likewise provide a binary 1 to gate 118-2 causing its output to set SCR 125-2 which, as was previously described with regard to SCR 125-1 will remain set. Each of the remaining 78 positions will be scanned in similar fashion until all 80 characters of the first line of print will be compared against the character in counter 101. As soon as the count in units and tens-circuits 119 and 120 reaches 80, output lines 120-8 and 119-10 will be in the binary 1 state indicating that the entire group of characters are to be printed. Lines 120-8 and 119-10 are applied to associated inputs of a gate 130 whose output goes to binary 0 state indicating the 80th count has been reached..This output level is applied to a delay circuit 131 causing .rest of the units and l0s circuits 119 and 120, respectively, and simultaneously causing the stepping of address register 96-1 and binary counter 101, Immediately prior to the reset operation the trigger pulse signal is applied to conductor bar 20 (shown as a wire in FIG. 8 for purposes of simplicity) 'to trigger all lamps of the array whose SCRs have been set, at the exact moment that the startingrow" passes beneath the honeycombed structure which guides the light from the lamp array to the interior surface of the image drum. The triggering of those lamps whose SCRs 125 have been set causes a discharge which short circuits the lamp, illuminating selected characters of the starting row and simultaneously resetting the set SCRs 125. Immediately following the application of the trigger pulse signal to bar 20, the binary 0 level developed by gate is passed by delay 131 to units and tens circuits 119 and 120 to reset these circuits, advance binary counter 101 to alter its code format to the next character (B) arranged in the next adjacent row to the starting row. The operation described above is repeated for each row in a similar fashion until all rows of the drum have been scanned.

The ignited lamps generate a flash of large intensity to be passed through its associated guiding channel within the honeycomb structure and thereby form a shaped beam conforming to the character passing beneath the light-guiding channel for lamp 11-1 so as to expose either a sensitized transfer drum or sensitized paper for a sufficient time duration and at a sufficient light intensity to cause the character to be printed after development of the sensitized material,

FIGS. 10 and 11 are elevational views of two alternative embodiments which may be employed for the final printing operation. As shown in FIG. 10, the lamp array 20 (not shown in detail in FIG. 10 for purposes of simplicity) will have selected ones of the lamps in the array energized by the printer logic circuits as shown in FIG. 8, causing bursts of high-intensity lights directed downwardly as shown by arrow to pass through selected characters of that row now passing beneath the lamp array and honeycomb light-guiding structure. The light will pass through the transparent portions of the image and be blocked by the remaining opaque portions of the drum causing the light rays to be shaped in the form of characters through which they have just passed. This light will impinge upon the surface of a paper sheet 151 fed from a sheet roll 152 between driving rollers 153,154. The paper then passes a cut marker 155 positioned beneath sheet 151 and designed to make a mark upon the under surface of the paper each time one page length of sheet has passed out marker 155. In a typical case, the cut marker may provide a mark upon the bottom surface of the sheet every 1 1 inches.

After passing the cut marker, sheet 151 passes through a charging source 156 to charge the paper with a light-sensitive material. This light-sensitive material is exposed at the printing location P and subsequently developed by a developing means 157 located down stream relative to the image drum and lamp array 40 and 20, respectively. After development, the image is fixed by fixing means 158. Driving rollers 159,160 continue to draw the sheet 151 in the direction shown by arrow 161. A cut mark detector 162 which may, for example, be a light sensitive device, will cause a cutter assembly 163 to be energized at a predetermined time after the cut mark.

In FIG. 11 wherein like elements are designated by like numerals, plain paper is fed from a supply roller 152 through driving rollers 153-154. Cut marker 155 imprints an identifying mark on the underside of the sheet in a manner previously described. The embodiment of FIG. 11 further includes a transfer drum assembly 164 positioned between image drum 40 and elongated sheet 151. The transfer drum is provided with alight-sensitive coating which passes beneath clockwise rotating image drum 40 as transfer drum 164 rotates in the counterclockwise direction. Light of bright intensity from selected ones of the discharge lamps passes downwardly, as shown by arrow 150, to activate the sensitive coating provided on transfer drum 164. The activated portions of the coating pass through a developer 165, causing the coating to be developed. The sensitive coating is then transferred to the upper surface of elongated sheet 151. A freewheeling backing roller 166 provides the necessary pressure between transfer drum 164 and sheet 151 to cause the transfer of the developed coating to the upper surface of the sheet. After transfer of the developed coating the transfer drum portion which has just engaged sheet 151 passes through corotron assemblies 167 and 168 to reactivate the sensitive coating on the surface of drum 164 in order to cause it to become sensitive to the next group of characters to be imaged upon the coating. This operation continues in a repetitive manner.

After the images have been transferred to sheet 151, the sheet passes beneath a fixer 158, driving rollers 159, 160 and cut mark detector 162 which activates cutter 163 to cut elongated sheet 151 into page size sheets in the same manner as was previously described.

FIG. 9 shows another preferred embodiment of the lamp array and image drum assembly utilized as a character-display system.

Briefly, surveying the field of character-display systems, it should be noted that there are various display devices available, most of which use some form of matrix, dot or bar arrangement generated by an electron beam upon a sensitive surface. The most commonly known display utilizes a cathode-ray tube which is controlled by character generating circuitry and performs the desired image upon the face of the cathode ray tube. The optical character quality of this type of device is poor since the characters are composed from a dot matrix or bar matrix. In addition to poor quality, it becomes very difficult and expensive to alter the display information pattern.

The technique utilized in the present invention is simple, inexpensive and offers quality approaching the print quality which is obtainable only from expensive special purpose systems.

Through a simple change in the mask provided in the image drum of FIG. 4, for example, it is possible to display alphanumeric information or other symbols, if desired, in any desired language. The device does not require an expensive character generator. The display light, spectral radiation is white and does not strain the eye of the observer. The panel can be viewed by several people at comfortable distances.

The principle of motion pictures resides in the fact that the human brain cannot distinguish motion of the frames at rates higher than frames per second. The present invention employs a device which has a transparent drum assembly 40 and a film negative 41 of the alphanumeric information wrapped around the periphery of the drum in the same manner as was previously described with respect to FIG. 4. It should be understood that whereas the film negative has an opaque background and transparent characters, the characters are shown in FIG. 11 as being black characters on a white" background merely for purposes of simplicity and presentation A source of synchronous signals is provided on the drum after which the location of each chara ter is fix d and th time at which the character will arrive at the display area is known. This is preformed through the utilization of the synchronous signal to operate the trigger electrodes of the lamp array.

When the desired character appears at the proper location, the flashlamp at that location is fired by means of logic circuitry and driving circuitry as was described with regard to FIG. 8. The illuminated image of the character shape is positioned immediately adjacent a groundglass screen to generate a visually observable display. The drum rotates at a speed of 1,200 rpm. The information to be displayed recirculates in the memory shift register 102 (see FIG. 8) and causes the lamps to be fired at the exact time required at each revolution of the drum. The information is repetitively displayed for each revolution of the drum until new information is applied to the logic and driving circuitry, thereby causing the display to change.

The ground glass 170 of FIG. 11 may be replaced by a transparent plate having a memory of phosphor coated on the surface of the plate 170 facing the lamp array. Means 171 may be provided for mechanically moving plate 170 (mechanical coupling being shown by dotted line 172) to cause a plurality of rows of characters to be displayed. The persistence of the memory phosphor may be of sufficient time duration to allow for the presentation of a large number of lines of characters wherein the first line of characters will still be visible even after the last line of characters has been formed upon the memory phosphor. As another obvious alternative, the plate containing the memory phosphor may be mounted in a stationary fashion and electronic means 173 may be provided to clear the line of characters being displayed upon the memory phosphor upon receipt of a signal from the logical control circuitry that a new group of characters is to be displayed. Other obvious modifications will become apparent, which modifications will not depart in spirit from the invention described herein. For example, the light transparent sheet of FIG. 11 may be a continuous loop entrained around four rollers to cause the light transparent sheet to assume a substantially hollow rectangular configuration. One face of the sheet is positionedin close proximity to the image drum location at which the light passes through a specific row. The interior surface of the closest loop sheet is coated with a memory phosphor. Suitable discrete stepping means may be mechanically coupled to one of the four rollers for stepping the sheet in a lineby-line fashion as each row of characters is formed upon the memory phosphor.

Although there has been described a preferred embodiment of this novel invention, many variations and modifications will now become apparent to those skilled in the art. Therefore, this invention is to be limited, not by the specific disclosure herein, but only by the appending claims.

What is claimed is:

1. A lamp array for illuminating discrete preselected regions upon a surface to be exposed comprising a plurality of lamps each having an envelope containing an ionizable gas;

a pair of electrodes extending into the interior of the lamp and having leads for connecting each lamp to an external driving circuit;

said lamps being arranged in spaced parallel fashion at regular intervals along an imaginary straight line;

an elongated bar of conductive material positioned along one side of said array immediately adjacent all of the lamps in the array;

the surface of said bar facing said array being highly reflective to reflect light rays impinging on said surface;

said conductive bar being adapted to trigger the ignition of those preselected lamps in the array whose energizing circuits have been activated.

2. The lamp array of claim 1 wherein said reflective surface is provided with a plurality of arcuate-shaped grooves each being adapted to receive and position the envelope portion of an associated lamp for concentrating light rays emitted from each lamp upon associated discrete areas of the surface being illuminated.

3. A lamp array for illuminating discrete areas upon a surface to be exposed comprising:

a hollow elongated envelope formed of a lighttransparent material;

said envelope being hermetically sealed and containing an ionizable gas;

a plurality of separator members being arrangedin spaced parallel fashion positioned within the interior of said envelope at regularly spaced intervals along the length of said envelope;

said members being formed of an insulating material;

each adjacent pair of said members forming a separate lamp compartment;

each of said compartments having an anode and cathode electrode extending into the interior of said envelope, each electrode having a lead extending toward the exterior of said envelope for connecting said electrodes to external driving circuits;

an elongated sheet of conductive material having an arcuate-shaped cross-sectional configuration; arcuate-shaped said sheet having a highly reflective finish along its concave surface;

said sheet concave surface being positioned immediately adjacent the surface of said envelope for concentrating light emitted from each of said lamp compartments upon said surface being exposed.

4. The lamp array of claim 3 wherein said sheet is provided with a lead adapted to connect said sheet to an external circuit for triggering the discharge of the lamps in the array.

5. Illumination means comprising:

a lamp array, and driving circuitry for selectively operating the array;

said lamp array being comprised of:

a plurality of lamps each having an envelope and anode and cathode electrodes extending into said envelope;

said lamps being arranged in spaced parallel fashion; I I

an elongated bar of conductive material positioned along one side of said array immediately adjacent all of the lamps in the array;

the surface of said bar facing said array being highly reflective;

said driving circuitry comprising:

a plurality of driving circuits each having output terminals being coupled across the anode and cathode electrodes of an associated lamp;

each of said driver circuits having input terminals;

a DC voltage source coupled in common across all of said input terminals;

a plurality of storage means each being coupled across the output terminals of an associated driving circuit;

a trigger circuit comprising a second voltage source;

switch means coupled between said second voltage source and said conductive bar; said switch means having a control terminal and being adapted to connect said second voltage source to said conductive bar only upon application of a trigger signal upon said control terminal.

6. The illumination means of claim 5 further comprising a plurality of second switch means each having first, second and control electrodes; I

the first and second electrodes of said second switch means being coupled between an associated one of said storage @253? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 1 64L 560 Dated Febru ary 3 1972 Inventor(s) Joseph M. Klockenbrick It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, 1ine'4, change "Path Computer Equipment Inc."

to --Uppster Corporation--.

Signed and sealed this 8th day of August 1972.

(SEAL) Attest:

EDWARD M.FLETCHER JR ROBERT GUTTSC HALK Attescing Officer Commissionerof Patents r $2 33 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTEON Patent No. 3 64] 5 0 Dated February 8, 1972 Inventor(s) Joseph M. Klockenbrick It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line change "Path Computer Equipment Inc."

to --Uppster Corporation--.

Signed am? sealed this 8th day of August 1972.

(SEAL) Attest:

EDWARD MELETCHER JR ROBERT GOTTSCHA'LK Attesting Officer Commissioner of Patents 

1. A lamp array for illuminating discrete preselected regions upon a surface to be exposed comprising a plurality of lamps each having an envelope containing an ionizable gas; a pair of electrodes extending into the interior of the lamp and having leads for connecting each lamp to an external driving circuit; said lamps being arranged in spaced parallel fashion at regular intervals along an imaginary straight line; an elongated bar of conductive material positioned along one side of said array immediately adjacent all of the lamps in the array; the surface of said bar facing said array being highly reflective to reflect light rays impinging on said surface; said conductive bar being adapted to trigger the ignition of those preselected lamps in the array whose energizing circuits have been activated.
 2. The lamp array of claim 1 wherein said reflective surface is provided with a plurality of arcuate-shaped grooves each being adapted to receive and position the envelope portion of an associated lamp for concentrating light rays emitted from each lamp upon associated discrete areas of the surface being illuminated.
 3. A lamp array for illuminating discrete areas upon a surface to be exposed comprising: a hollow elongated envelope formed of a light-transparent material; said envelope being hermetically sealed and containing an ionizable gas; a plurality of separator members being arranged in spaced parallel fashion positioned within the interior of said envelope at regularly spaced intervals along the length of said envelope; said members being formed of an insulating material; each adjacent pair of said members forming a separate lamp compartment; each of said compartments having an anode and cathode electrode extending into the interior of said envelope, each electrode having a lead extending toward the exterior of said envelope for connecting said electrodes to external driving circuits; an elongated sheet of conductive material having an arcuate-shaped cross-sectional configuration; said sheet having a highly reflective finish along its concave surface; said sheet concave surface being positioned immediately adjacent the surface of said envelope for concentrating light emitted from each of said lamp compartments upon said surface being exposed.
 4. The lamp array of claim 3 wherein said sheet is provided with a lead adapted to connect said sheet to an external circuit for triggering the discharge of the lamps in the array.
 5. Illumination means comprising: a lamp array, and driving circuitry for selectively operating the array; said lamp array being comprised of: a plurality of lamps each having an envelope and anode and cathode electrodes extending into said envelope; said lamps being arranged in spaced parallel fashion; an elongated bar of conductive material positioned along one side of said array immediately adjacent all of the lamps in the array; the surface of said bar facing said array being highly reflective; said driving circuitry comprising: a plurality of driving circuits each having output terminals being coupled across the anode and cathode electrodes of an associated lamp; each of said driver circuits having input terminals; a DC voltage source coupled in common across all of said input terminals; a plurality of storage means each being coupled across the output terminals of an associated driving circuit; a trigger circuit comprising a second voltage source; switch means coupled between said second voltage source and said conductive bar; said switch means having a control terminal and being adapted to connect said second voltage source to said conductive bar only upon application of a trigger signal upon said control terminal.
 6. The illumination means of claim 5 further comprising a plurality of second switch means each having first, second and control electrodes; the first and second electrodes of said second switch means being coupled between an associated one of said storage means and said lamps and being normally nonconductive; lamp-selecting means for selectively rendering said plurality of second switch means conductive having a plurality of output terminals each connected to an associated one of said control electrodes; said lamp-selecting means including means for momentarily applying a pulse to those control electrodes whose lamps have been selected to ignite; each of said second switch means being adapted to remain in the conductive state after said momentary pulses are removed and to return to the nonconductive state only upon discharge of its associated lamp. 